David,

Good information here, but what if you're seeing a mixture of waits on empty
and full buffers?  My numbers seem to be spread pretty evenly, though I do
get slightly more waits for empty buffers on a daily basis...

Ken Zufall
Technical Analyst
Phone: 216.471.3613
Pager: 440.303.1656
Fax: 216.491.4051

"It's not the most intellectual job, but I do have to know all the letters."
Vanna White



                -----Original Message-----
                From:   David A. Chapa [mailto:david AT datastaff DOT com]
                Sent:   Tuesday, February 20, 2001 11:13 AM
                To:     Caddell, Scott; veritas-bu AT mailman.eng.auburn DOT edu
                Cc:     Nbu-Lserv@Datastaff. Com
                Subject:        [Veritas-bu] RE: [NBUADV-L]: Performance
Tuning
                Sensitivity:    Confidential

                Scott:

                I've never created the keys, but what I have done (on NT) is
to create the
                files NUMBER_DATA_BUFFERS and SIZE_DATA_BUFFERS in
                /veritas/netbackup/db/config, which works just as well.

                As far as guidelines goes, I would first create a bptm log
and begin
                monitoring the performance of your media servers (these
buffer files will
                only need to be created on the MEDIA SERVERS).

                Based on the information you gleen from there, I would make
my changes from
                default (8x32 - 8 DATA BUFFERS x 32K ea for non multiplex
and 8x64 for
                multiplex).

                My own experience has been that I have seen increased
performance when I
                decrease the number of buffers and increase the size, but
your mileage may
                vary depending on your own environment.

                What to look for in the bptm logs?

                waited for full buffer

                this is the number of times bptm had to wait for a full
buffer.  This would
                indicate less data coming from the network, so adding more
buffers will not
                help, but perhaps reducing the number of buffers *MIGHT*.

                waited for empty buffer

                how many times bptm had to wait for the buffer to empty.
This would
                indicate more data coming from the network than the drive
can handle so more
                buffers would apply here.

                The delayed xxxxx times in the logs message

                is the number of time bptm waited in the loop for an
available buffer (30ms
                delay ea. time)


                Hope this helps.

                David



                <><><><><><><><><><><><><><><><><><><><>
                David A. Chapa
                Consulting Manager
                DataStaff, Inc.
                847 413 1144
                http://www.consulting.datastaff.com
                ---------------------------------------
                NBU-LSERV AT datastaff DOT com - Adv. Scripting

                -----Original Message-----
                From: owner-nbu-lserv AT datastaff DOT com
                [mailto:owner-nbu-lserv AT datastaff DOT com]On Behalf Of 
Caddell,
Scott
                Sent: Tuesday, February 20, 2001 9:44 AM
                To: veritas-bu AT mailman.eng.auburn DOT edu
                Cc: Nbu-Lserv@Datastaff. Com
                Subject: [NBUADV-L]: Performance Tuning
                Sensitivity: Confidential


                I need to do some SCSI performance tuning on my W2K Master
(3.4).  I am
                pretty
                sure I need to create some registry keys in
HKLM/Software/Veritas/config
                called
                Number_Data_Buffers and Size_Data_Buffers, but I'm not sure
on how I should
                set
                the values.  Does anyone have information on creating these
keys and a
                guideline
                on tuning?

                Thanks,

                Scott Caddell
                Intersil Corporation
                Palm Bay, FL
                -------------------------------------------------------
                NBU-LSERV AT datastaff DOT com - Advanced NetBackup Scripting
                http://www.consulting.datastaff.com/adv_script_site


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